GridLayoutManager.java revision 906659fc65e7b8b1bc9f0c7cc3dabf7e64e8b9bf
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14package android.support.v17.leanback.widget; 15 16import android.content.Context; 17import android.graphics.PointF; 18import android.graphics.Rect; 19import android.os.Bundle; 20import android.os.Parcel; 21import android.os.Parcelable; 22import android.support.v4.view.ViewCompat; 23import android.support.v7.widget.LinearSmoothScroller; 24import android.support.v7.widget.RecyclerView; 25import android.support.v7.widget.RecyclerView.Recycler; 26import android.support.v7.widget.RecyclerView.State; 27 28import static android.support.v7.widget.RecyclerView.NO_ID; 29import static android.support.v7.widget.RecyclerView.NO_POSITION; 30import static android.support.v7.widget.RecyclerView.HORIZONTAL; 31import static android.support.v7.widget.RecyclerView.VERTICAL; 32 33import android.util.AttributeSet; 34import android.util.Log; 35import android.view.FocusFinder; 36import android.view.Gravity; 37import android.view.View; 38import android.view.ViewParent; 39import android.view.View.MeasureSpec; 40import android.view.ViewGroup.MarginLayoutParams; 41import android.view.ViewGroup; 42 43import java.io.PrintWriter; 44import java.io.StringWriter; 45import java.util.ArrayList; 46import java.util.List; 47 48final class GridLayoutManager extends RecyclerView.LayoutManager { 49 50 /* 51 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 52 * The class currently does two internal jobs: 53 * - Saves optical bounds insets. 54 * - Caches focus align view center. 55 */ 56 static class LayoutParams extends RecyclerView.LayoutParams { 57 58 // The view is saved only during animation. 59 private View mView; 60 61 // For placement 62 private int mLeftInset; 63 private int mTopInset; 64 private int mRighInset; 65 private int mBottomInset; 66 67 // For alignment 68 private int mAlignX; 69 private int mAlignY; 70 71 public LayoutParams(Context c, AttributeSet attrs) { 72 super(c, attrs); 73 } 74 75 public LayoutParams(int width, int height) { 76 super(width, height); 77 } 78 79 public LayoutParams(MarginLayoutParams source) { 80 super(source); 81 } 82 83 public LayoutParams(ViewGroup.LayoutParams source) { 84 super(source); 85 } 86 87 public LayoutParams(RecyclerView.LayoutParams source) { 88 super(source); 89 } 90 91 public LayoutParams(LayoutParams source) { 92 super(source); 93 } 94 95 int getAlignX() { 96 return mAlignX; 97 } 98 99 int getAlignY() { 100 return mAlignY; 101 } 102 103 int getOpticalLeft(View view) { 104 return view.getLeft() + mLeftInset; 105 } 106 107 int getOpticalTop(View view) { 108 return view.getTop() + mTopInset; 109 } 110 111 int getOpticalRight(View view) { 112 return view.getRight() - mRighInset; 113 } 114 115 int getOpticalBottom(View view) { 116 return view.getBottom() - mBottomInset; 117 } 118 119 int getOpticalWidth(View view) { 120 return view.getWidth() - mLeftInset - mRighInset; 121 } 122 123 int getOpticalHeight(View view) { 124 return view.getHeight() - mTopInset - mBottomInset; 125 } 126 127 int getOpticalLeftInset() { 128 return mLeftInset; 129 } 130 131 int getOpticalRightInset() { 132 return mRighInset; 133 } 134 135 int getOpticalTopInset() { 136 return mTopInset; 137 } 138 139 int getOpticalBottomInset() { 140 return mBottomInset; 141 } 142 143 void setAlignX(int alignX) { 144 mAlignX = alignX; 145 } 146 147 void setAlignY(int alignY) { 148 mAlignY = alignY; 149 } 150 151 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 152 mLeftInset = leftInset; 153 mTopInset = topInset; 154 mRighInset = rightInset; 155 mBottomInset = bottomInset; 156 } 157 158 private void invalidateItemDecoration() { 159 ViewParent parent = mView.getParent(); 160 if (parent instanceof RecyclerView) { 161 // TODO: we only need invalidate parent if it has ItemDecoration 162 ((RecyclerView) parent).invalidate(); 163 } 164 } 165 } 166 167 private static final String TAG = "GridLayoutManager"; 168 private static final boolean DEBUG = false; 169 170 private String getTag() { 171 return TAG + ":" + mBaseGridView.getId(); 172 } 173 174 private final BaseGridView mBaseGridView; 175 176 /** 177 * The orientation of a "row". 178 */ 179 private int mOrientation = HORIZONTAL; 180 181 private RecyclerView.State mState; 182 private RecyclerView.Recycler mRecycler; 183 184 private boolean mInLayout = false; 185 private boolean mInSelection = false; 186 187 private OnChildSelectedListener mChildSelectedListener = null; 188 189 /** 190 * The focused position, it's not the currently visually aligned position 191 * but it is the final position that we intend to focus on. If there are 192 * multiple setSelection() called, mFocusPosition saves last value. 193 */ 194 private int mFocusPosition = NO_POSITION; 195 196 /** 197 * The offset to be applied to mFocusPosition, due to adapter change, on the next 198 * layout. Set to Integer.MIN_VALUE means item was removed. 199 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 200 * unfortunately cleared after prelayout. 201 */ 202 private int mFocusPositionOffset = 0; 203 204 /** 205 * Force a full layout under certain situations. 206 */ 207 private boolean mForceFullLayout; 208 209 /** 210 * True if layout is enabled. 211 */ 212 private boolean mLayoutEnabled = true; 213 214 /** 215 * The scroll offsets of the viewport relative to the entire view. 216 */ 217 private int mScrollOffsetPrimary; 218 private int mScrollOffsetSecondary; 219 220 /** 221 * User-specified row height/column width. Can be WRAP_CONTENT. 222 */ 223 private int mRowSizeSecondaryRequested; 224 225 /** 226 * The fixed size of each grid item in the secondary direction. This corresponds to 227 * the row height, equal for all rows. Grid items may have variable length 228 * in the primary direction. 229 */ 230 private int mFixedRowSizeSecondary; 231 232 /** 233 * Tracks the secondary size of each row. 234 */ 235 private int[] mRowSizeSecondary; 236 237 /** 238 * Flag controlling whether the current/next layout should 239 * be updating the secondary size of rows. 240 */ 241 private boolean mRowSecondarySizeRefresh; 242 243 /** 244 * The maximum measured size of the view. 245 */ 246 private int mMaxSizeSecondary; 247 248 /** 249 * Margin between items. 250 */ 251 private int mHorizontalMargin; 252 /** 253 * Margin between items vertically. 254 */ 255 private int mVerticalMargin; 256 /** 257 * Margin in main direction. 258 */ 259 private int mMarginPrimary; 260 /** 261 * Margin in second direction. 262 */ 263 private int mMarginSecondary; 264 /** 265 * How to position child in secondary direction. 266 */ 267 private int mGravity = Gravity.LEFT | Gravity.TOP; 268 /** 269 * The number of rows in the grid. 270 */ 271 private int mNumRows; 272 /** 273 * Number of rows requested, can be 0 to be determined by parent size and 274 * rowHeight. 275 */ 276 private int mNumRowsRequested = 1; 277 278 /** 279 * Tracking start/end position of each row for visible items. 280 */ 281 private StaggeredGrid.Row[] mRows; 282 283 /** 284 * Saves grid information of each view. 285 */ 286 private StaggeredGrid mGrid; 287 /** 288 * Position of first item (included) that has attached views. 289 */ 290 private int mFirstVisiblePos; 291 /** 292 * Position of last item (included) that has attached views. 293 */ 294 private int mLastVisiblePos; 295 296 /** 297 * Focus Scroll strategy. 298 */ 299 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 300 /** 301 * Defines how item view is aligned in the window. 302 */ 303 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 304 305 /** 306 * Defines how item view is aligned. 307 */ 308 private final ItemAlignment mItemAlignment = new ItemAlignment(); 309 310 /** 311 * Dimensions of the view, width or height depending on orientation. 312 */ 313 private int mSizePrimary; 314 315 /** 316 * Allow DPAD key to navigate out at the front of the View (where position = 0), 317 * default is false. 318 */ 319 private boolean mFocusOutFront; 320 321 /** 322 * Allow DPAD key to navigate out at the end of the view, default is false. 323 */ 324 private boolean mFocusOutEnd; 325 326 /** 327 * True if focus search is disabled. 328 */ 329 private boolean mFocusSearchDisabled; 330 331 /** 332 * True if prune child, might be disabled during transition. 333 */ 334 private boolean mPruneChild = true; 335 336 /** 337 * True if scroll content, might be disabled during transition. 338 */ 339 private boolean mScrollEnabled = true; 340 341 private int[] mTempDeltas = new int[2]; 342 343 /** 344 * Temporaries used for measuring. 345 */ 346 private int[] mMeasuredDimension = new int[2]; 347 348 SavedState mLoadingState; 349 final ViewsStateBundle mChildrenStates = new ViewsStateBundle( 350 ViewsStateBundle.SAVE_LIMITED_CHILD, ViewsStateBundle.DEFAULT_LIMIT); 351 352 public GridLayoutManager(BaseGridView baseGridView) { 353 mBaseGridView = baseGridView; 354 } 355 356 public void setOrientation(int orientation) { 357 if (orientation != HORIZONTAL && orientation != VERTICAL) { 358 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 359 return; 360 } 361 362 mOrientation = orientation; 363 mWindowAlignment.setOrientation(orientation); 364 mItemAlignment.setOrientation(orientation); 365 mForceFullLayout = true; 366 } 367 368 public int getFocusScrollStrategy() { 369 return mFocusScrollStrategy; 370 } 371 372 public void setFocusScrollStrategy(int focusScrollStrategy) { 373 mFocusScrollStrategy = focusScrollStrategy; 374 } 375 376 public void setWindowAlignment(int windowAlignment) { 377 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 378 } 379 380 public int getWindowAlignment() { 381 return mWindowAlignment.mainAxis().getWindowAlignment(); 382 } 383 384 public void setWindowAlignmentOffset(int alignmentOffset) { 385 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 386 } 387 388 public int getWindowAlignmentOffset() { 389 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 390 } 391 392 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 393 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 394 } 395 396 public float getWindowAlignmentOffsetPercent() { 397 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 398 } 399 400 public void setItemAlignmentOffset(int alignmentOffset) { 401 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 402 updateChildAlignments(); 403 } 404 405 public int getItemAlignmentOffset() { 406 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 407 } 408 409 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 410 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 411 updateChildAlignments(); 412 } 413 414 public boolean isItemAlignmentOffsetWithPadding() { 415 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 416 } 417 418 public void setItemAlignmentOffsetPercent(float offsetPercent) { 419 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 420 updateChildAlignments(); 421 } 422 423 public float getItemAlignmentOffsetPercent() { 424 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 425 } 426 427 public void setItemAlignmentViewId(int viewId) { 428 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 429 updateChildAlignments(); 430 } 431 432 public int getItemAlignmentViewId() { 433 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 434 } 435 436 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 437 mFocusOutFront = throughFront; 438 mFocusOutEnd = throughEnd; 439 } 440 441 public void setNumRows(int numRows) { 442 if (numRows < 0) throw new IllegalArgumentException(); 443 mNumRowsRequested = numRows; 444 mForceFullLayout = true; 445 } 446 447 /** 448 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 449 */ 450 public void setRowHeight(int height) { 451 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 452 mRowSizeSecondaryRequested = height; 453 } else { 454 throw new IllegalArgumentException("Invalid row height: " + height); 455 } 456 } 457 458 public void setItemMargin(int margin) { 459 mVerticalMargin = mHorizontalMargin = margin; 460 mMarginPrimary = mMarginSecondary = margin; 461 } 462 463 public void setVerticalMargin(int margin) { 464 if (mOrientation == HORIZONTAL) { 465 mMarginSecondary = mVerticalMargin = margin; 466 } else { 467 mMarginPrimary = mVerticalMargin = margin; 468 } 469 } 470 471 public void setHorizontalMargin(int margin) { 472 if (mOrientation == HORIZONTAL) { 473 mMarginPrimary = mHorizontalMargin = margin; 474 } else { 475 mMarginSecondary = mHorizontalMargin = margin; 476 } 477 } 478 479 public int getVerticalMargin() { 480 return mVerticalMargin; 481 } 482 483 public int getHorizontalMargin() { 484 return mHorizontalMargin; 485 } 486 487 public void setGravity(int gravity) { 488 mGravity = gravity; 489 } 490 491 protected boolean hasDoneFirstLayout() { 492 return mGrid != null; 493 } 494 495 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 496 mChildSelectedListener = listener; 497 } 498 499 private int getPositionByView(View view) { 500 if (view == null) { 501 return NO_POSITION; 502 } 503 LayoutParams params = (LayoutParams) view.getLayoutParams(); 504 if (params == null || params.isItemRemoved()) { 505 // when item is removed, the position value can be any value. 506 return NO_POSITION; 507 } 508 return params.getViewPosition(); 509 } 510 511 private int getPositionByIndex(int index) { 512 return getPositionByView(getChildAt(index)); 513 } 514 515 private void dispatchChildSelected() { 516 if (mChildSelectedListener == null) { 517 return; 518 } 519 if (mFocusPosition != NO_POSITION) { 520 View view = findViewByPosition(mFocusPosition); 521 if (view != null) { 522 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 523 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 524 vh == null? NO_ID: vh.getItemId()); 525 return; 526 } 527 } 528 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 529 } 530 531 @Override 532 public boolean canScrollHorizontally() { 533 // We can scroll horizontally if we have horizontal orientation, or if 534 // we are vertical and have more than one column. 535 return mOrientation == HORIZONTAL || mNumRows > 1; 536 } 537 538 @Override 539 public boolean canScrollVertically() { 540 // We can scroll vertically if we have vertical orientation, or if we 541 // are horizontal and have more than one row. 542 return mOrientation == VERTICAL || mNumRows > 1; 543 } 544 545 @Override 546 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 547 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 548 ViewGroup.LayoutParams.WRAP_CONTENT); 549 } 550 551 @Override 552 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 553 return new LayoutParams(context, attrs); 554 } 555 556 @Override 557 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 558 if (lp instanceof LayoutParams) { 559 return new LayoutParams((LayoutParams) lp); 560 } else if (lp instanceof RecyclerView.LayoutParams) { 561 return new LayoutParams((RecyclerView.LayoutParams) lp); 562 } else if (lp instanceof MarginLayoutParams) { 563 return new LayoutParams((MarginLayoutParams) lp); 564 } else { 565 return new LayoutParams(lp); 566 } 567 } 568 569 protected View getViewForPosition(int position) { 570 return mRecycler.getViewForPosition(position); 571 } 572 573 final int getOpticalLeft(View v) { 574 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 575 } 576 577 final int getOpticalRight(View v) { 578 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 579 } 580 581 final int getOpticalTop(View v) { 582 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 583 } 584 585 final int getOpticalBottom(View v) { 586 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 587 } 588 589 private int getViewMin(View v) { 590 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 591 } 592 593 private int getViewMax(View v) { 594 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 595 } 596 597 private int getViewCenter(View view) { 598 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 599 } 600 601 private int getViewCenterSecondary(View view) { 602 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 603 } 604 605 private int getViewCenterX(View v) { 606 LayoutParams p = (LayoutParams) v.getLayoutParams(); 607 return p.getOpticalLeft(v) + p.getAlignX(); 608 } 609 610 private int getViewCenterY(View v) { 611 LayoutParams p = (LayoutParams) v.getLayoutParams(); 612 return p.getOpticalTop(v) + p.getAlignY(); 613 } 614 615 /** 616 * Save Recycler and State for convenience. Must be paired with leaveContext(). 617 */ 618 private void saveContext(Recycler recycler, State state) { 619 if (mRecycler != null || mState != null) { 620 Log.e(TAG, "Recycler information was not released, bug!"); 621 } 622 mRecycler = recycler; 623 mState = state; 624 } 625 626 /** 627 * Discard saved Recycler and State. 628 */ 629 private void leaveContext() { 630 mRecycler = null; 631 mState = null; 632 } 633 634 /** 635 * Re-initialize data structures for a data change or handling invisible 636 * selection. The method tries its best to preserve position information so 637 * that staggered grid looks same before and after re-initialize. 638 * @param focusPosition The initial focusPosition that we would like to 639 * focus on. 640 * @return Actual position that can be focused on. 641 */ 642 private int init(int focusPosition) { 643 644 final int newItemCount = mState.getItemCount(); 645 646 if (focusPosition == NO_POSITION && newItemCount > 0) { 647 // if focus position is never set before, initialize it to 0 648 focusPosition = 0; 649 } 650 // If adapter has changed then caches are invalid; otherwise, 651 // we try to maintain each row's position if number of rows keeps the same 652 // and existing mGrid contains the focusPosition. 653 if (mRows != null && mNumRows == mRows.length && 654 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 655 focusPosition >= mGrid.getFirstIndex() && 656 focusPosition <= mGrid.getLastIndex()) { 657 // strip mGrid to a subset (like a column) that contains focusPosition 658 mGrid.stripDownTo(focusPosition); 659 // make sure that remaining items do not exceed new adapter size 660 int firstIndex = mGrid.getFirstIndex(); 661 int lastIndex = mGrid.getLastIndex(); 662 if (DEBUG) { 663 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 664 } 665 for (int i = lastIndex; i >=firstIndex; i--) { 666 if (i >= newItemCount) { 667 mGrid.removeLast(); 668 } 669 } 670 if (mGrid.getSize() == 0) { 671 focusPosition = newItemCount - 1; 672 // initialize row start locations 673 for (int i = 0; i < mNumRows; i++) { 674 mRows[i].low = 0; 675 mRows[i].high = 0; 676 } 677 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 678 } else { 679 // initialize row start locations 680 for (int i = 0; i < mNumRows; i++) { 681 mRows[i].low = Integer.MAX_VALUE; 682 mRows[i].high = Integer.MIN_VALUE; 683 } 684 firstIndex = mGrid.getFirstIndex(); 685 lastIndex = mGrid.getLastIndex(); 686 if (focusPosition > lastIndex) { 687 focusPosition = mGrid.getLastIndex(); 688 } 689 if (DEBUG) { 690 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 691 + lastIndex + " focusPosition " + focusPosition); 692 } 693 // fill rows with minimal view positions of the subset 694 for (int i = firstIndex; i <= lastIndex; i++) { 695 View v = findViewByPosition(i); 696 if (v == null) { 697 continue; 698 } 699 int row = mGrid.getLocation(i).row; 700 int low = getViewMin(v) + mScrollOffsetPrimary; 701 if (low < mRows[row].low) { 702 mRows[row].low = mRows[row].high = low; 703 } 704 } 705 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 706 if (firstItemRowPosition == Integer.MAX_VALUE) { 707 firstItemRowPosition = 0; 708 } 709 if (mState.didStructureChange()) { 710 // if there is structure change, the removed item might be in the 711 // subset, so it is meaningless to maintain the low locations. 712 for (int i = 0; i < mNumRows; i++) { 713 mRows[i].low = firstItemRowPosition; 714 mRows[i].high = firstItemRowPosition; 715 } 716 } else { 717 // fill other rows that does not include the subset using first item 718 for (int i = 0; i < mNumRows; i++) { 719 if (mRows[i].low == Integer.MAX_VALUE) { 720 mRows[i].low = mRows[i].high = firstItemRowPosition; 721 } 722 } 723 } 724 } 725 726 // Same adapter, we can reuse any attached views 727 detachAndScrapAttachedViews(mRecycler); 728 729 } else { 730 // otherwise recreate data structure 731 mRows = new StaggeredGrid.Row[mNumRows]; 732 733 for (int i = 0; i < mNumRows; i++) { 734 mRows[i] = new StaggeredGrid.Row(); 735 } 736 mGrid = new StaggeredGridDefault(); 737 if (newItemCount == 0) { 738 focusPosition = NO_POSITION; 739 } else if (focusPosition >= newItemCount) { 740 focusPosition = newItemCount - 1; 741 } 742 743 // Adapter may have changed so remove all attached views permanently 744 removeAndRecycleAllViews(mRecycler); 745 746 mScrollOffsetPrimary = 0; 747 mScrollOffsetSecondary = 0; 748 mWindowAlignment.reset(); 749 } 750 751 mGrid.setProvider(mGridProvider); 752 // mGrid share the same Row array information 753 mGrid.setRows(mRows); 754 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 755 756 initScrollController(); 757 updateScrollSecondAxis(); 758 759 return focusPosition; 760 } 761 762 private int getRowSizeSecondary(int rowIndex) { 763 if (mFixedRowSizeSecondary != 0) { 764 return mFixedRowSizeSecondary; 765 } 766 if (mRowSizeSecondary == null) { 767 return 0; 768 } 769 return mRowSizeSecondary[rowIndex]; 770 } 771 772 private int getRowStartSecondary(int rowIndex) { 773 int start = 0; 774 for (int i = 0; i < rowIndex; i++) { 775 start += getRowSizeSecondary(i) + mMarginSecondary; 776 } 777 return start; 778 } 779 780 private int getSizeSecondary() { 781 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 782 } 783 784 private void measureScrapChild(int position, int widthSpec, int heightSpec, 785 int[] measuredDimension) { 786 View view = mRecycler.getViewForPosition(position); 787 if (view != null) { 788 LayoutParams p = (LayoutParams) view.getLayoutParams(); 789 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 790 getPaddingLeft() + getPaddingRight(), p.width); 791 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 792 getPaddingTop() + getPaddingBottom(), p.height); 793 view.measure(childWidthSpec, childHeightSpec); 794 measuredDimension[0] = view.getMeasuredWidth(); 795 measuredDimension[1] = view.getMeasuredHeight(); 796 mRecycler.recycleView(view); 797 } 798 } 799 800 private boolean processRowSizeSecondary(boolean measure) { 801 if (mFixedRowSizeSecondary != 0) { 802 return false; 803 } 804 805 List<Integer>[] rows = mGrid == null ? null : 806 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 807 boolean changed = false; 808 int scrapChildWidth = -1; 809 int scrapChildHeight = -1; 810 811 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 812 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 813 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 814 " rowItemCount " + rowItemCount); 815 816 int rowSize = -1; 817 for (int i = 0; i < rowItemCount; i++) { 818 final View view = findViewByPosition(rows[rowIndex].get(i)); 819 if (view == null) { 820 continue; 821 } 822 if (measure && view.isLayoutRequested()) { 823 measureChild(view); 824 } 825 final int secondarySize = mOrientation == HORIZONTAL ? 826 view.getMeasuredHeight() : view.getMeasuredWidth(); 827 if (secondarySize > rowSize) { 828 rowSize = secondarySize; 829 } 830 } 831 832 if (measure && rowSize < 0 && mState.getItemCount() > 0) { 833 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 834 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 835 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 836 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 837 mMeasuredDimension); 838 scrapChildWidth = mMeasuredDimension[0]; 839 scrapChildHeight = mMeasuredDimension[1]; 840 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 841 " " + scrapChildHeight); 842 } 843 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 844 } 845 846 if (rowSize < 0) { 847 rowSize = 0; 848 } 849 850 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 851 " rowSize " + rowSize); 852 853 if (mRowSizeSecondary[rowIndex] != rowSize) { 854 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 855 ", " + rowSize); 856 857 mRowSizeSecondary[rowIndex] = rowSize; 858 changed = true; 859 } 860 } 861 862 return changed; 863 } 864 865 /** 866 * Checks if we need to update row secondary sizes. 867 */ 868 private void updateRowSecondarySizeRefresh() { 869 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 870 if (mRowSecondarySizeRefresh) { 871 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 872 forceRequestLayout(); 873 } 874 } 875 876 private void forceRequestLayout() { 877 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 878 // RecyclerView prevents us from requesting layout in many cases 879 // (during layout, during scroll, etc.) 880 // For secondary row size wrap_content support we currently need a 881 // second layout pass to update the measured size after having measured 882 // and added child views in layoutChildren. 883 // Force the second layout by posting a delayed runnable. 884 // TODO: investigate allowing a second layout pass, 885 // or move child add/measure logic to the measure phase. 886 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 887 } 888 889 private final Runnable mRequestLayoutRunnable = new Runnable() { 890 @Override 891 public void run() { 892 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 893 requestLayout(); 894 } 895 }; 896 897 @Override 898 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 899 saveContext(recycler, state); 900 901 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 902 int measuredSizeSecondary; 903 if (mOrientation == HORIZONTAL) { 904 sizePrimary = MeasureSpec.getSize(widthSpec); 905 sizeSecondary = MeasureSpec.getSize(heightSpec); 906 modeSecondary = MeasureSpec.getMode(heightSpec); 907 paddingSecondary = getPaddingTop() + getPaddingBottom(); 908 } else { 909 sizeSecondary = MeasureSpec.getSize(widthSpec); 910 sizePrimary = MeasureSpec.getSize(heightSpec); 911 modeSecondary = MeasureSpec.getMode(widthSpec); 912 paddingSecondary = getPaddingLeft() + getPaddingRight(); 913 } 914 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 915 " heightSpec " + Integer.toHexString(heightSpec) + 916 " modeSecondary " + Integer.toHexString(modeSecondary) + 917 " sizeSecondary " + sizeSecondary + " " + this); 918 919 mMaxSizeSecondary = sizeSecondary; 920 921 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 922 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 923 mFixedRowSizeSecondary = 0; 924 925 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 926 mRowSizeSecondary = new int[mNumRows]; 927 } 928 929 // Measure all current children and update cached row heights 930 processRowSizeSecondary(true); 931 932 switch (modeSecondary) { 933 case MeasureSpec.UNSPECIFIED: 934 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 935 break; 936 case MeasureSpec.AT_MOST: 937 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 938 mMaxSizeSecondary); 939 break; 940 case MeasureSpec.EXACTLY: 941 measuredSizeSecondary = mMaxSizeSecondary; 942 break; 943 default: 944 throw new IllegalStateException("wrong spec"); 945 } 946 947 } else { 948 switch (modeSecondary) { 949 case MeasureSpec.UNSPECIFIED: 950 if (mRowSizeSecondaryRequested == 0) { 951 if (mOrientation == HORIZONTAL) { 952 throw new IllegalStateException("Must specify rowHeight or view height"); 953 } else { 954 throw new IllegalStateException("Must specify columnWidth or view width"); 955 } 956 } 957 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 958 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 959 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 960 * (mNumRows - 1) + paddingSecondary; 961 break; 962 case MeasureSpec.AT_MOST: 963 case MeasureSpec.EXACTLY: 964 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 965 mNumRows = 1; 966 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 967 } else if (mNumRowsRequested == 0) { 968 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 969 mNumRows = (sizeSecondary + mMarginSecondary) 970 / (mRowSizeSecondaryRequested + mMarginSecondary); 971 } else if (mRowSizeSecondaryRequested == 0) { 972 mNumRows = mNumRowsRequested; 973 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 974 * (mNumRows - 1)) / mNumRows; 975 } else { 976 mNumRows = mNumRowsRequested; 977 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 978 } 979 measuredSizeSecondary = sizeSecondary; 980 if (modeSecondary == MeasureSpec.AT_MOST) { 981 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 982 * (mNumRows - 1) + paddingSecondary; 983 if (childrenSize < measuredSizeSecondary) { 984 measuredSizeSecondary = childrenSize; 985 } 986 } 987 break; 988 default: 989 throw new IllegalStateException("wrong spec"); 990 } 991 } 992 if (mOrientation == HORIZONTAL) { 993 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 994 } else { 995 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 996 } 997 if (DEBUG) { 998 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 999 " measuredSizeSecondary " + measuredSizeSecondary + 1000 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1001 " mNumRows " + mNumRows); 1002 } 1003 1004 leaveContext(); 1005 } 1006 1007 private void measureChild(View child) { 1008 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1009 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1010 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1011 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1012 int widthSpec, heightSpec; 1013 1014 if (mOrientation == HORIZONTAL) { 1015 widthSpec = ViewGroup.getChildMeasureSpec( 1016 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1017 0, lp.width); 1018 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1019 } else { 1020 heightSpec = ViewGroup.getChildMeasureSpec( 1021 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1022 0, lp.height); 1023 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1024 } 1025 1026 child.measure(widthSpec, heightSpec); 1027 1028 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1029 " widthSpec " + Integer.toHexString(widthSpec) + 1030 " heightSpec " + Integer.toHexString(heightSpec) + 1031 " measuredWidth " + child.getMeasuredWidth() + 1032 " measuredHeight " + child.getMeasuredHeight()); 1033 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1034 } 1035 1036 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1037 1038 @Override 1039 public int getCount() { 1040 return mState.getItemCount(); 1041 } 1042 1043 @Override 1044 public void createItem(int index, int rowIndex, boolean append) { 1045 View v = getViewForPosition(index); 1046 if (mFirstVisiblePos >= 0) { 1047 // when StaggeredGrid append or prepend item, we must guarantee 1048 // that sibling item has created views already. 1049 if (append && index != mLastVisiblePos + 1) { 1050 throw new RuntimeException(); 1051 } else if (!append && index != mFirstVisiblePos - 1) { 1052 throw new RuntimeException(); 1053 } 1054 } 1055 1056 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1057 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1058 if (append) { 1059 addView(v); 1060 } else { 1061 addView(v, 0); 1062 } 1063 measureChild(v); 1064 } 1065 1066 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1067 int start, end; 1068 if (append) { 1069 start = mRows[rowIndex].high; 1070 if (start != mRows[rowIndex].low) { 1071 // if there are existing item in the row, add margin between 1072 start += mMarginPrimary; 1073 } else { 1074 final int lastRow = mRows.length - 1; 1075 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1076 // if there are existing item in the last row, insert 1077 // the new item after the last item of last row. 1078 start = mRows[lastRow].high + mMarginPrimary; 1079 } 1080 } 1081 end = start + length; 1082 mRows[rowIndex].high = end; 1083 } else { 1084 end = mRows[rowIndex].low; 1085 if (end != mRows[rowIndex].high) { 1086 end -= mMarginPrimary; 1087 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1088 // if there are existing item in the first row, insert 1089 // the new item before the first item of first row. 1090 end = mRows[0].low - mMarginPrimary; 1091 } 1092 start = end - length; 1093 mRows[rowIndex].low = start; 1094 } 1095 if (mFirstVisiblePos < 0) { 1096 mFirstVisiblePos = mLastVisiblePos = index; 1097 } else { 1098 if (append) { 1099 mLastVisiblePos++; 1100 } else { 1101 mFirstVisiblePos--; 1102 } 1103 } 1104 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1105 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1106 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1107 startSecondary); 1108 if (DEBUG) { 1109 Log.d(getTag(), "addView " + index + " " + v); 1110 } 1111 if (index == mFirstVisiblePos) { 1112 updateScrollMin(); 1113 } 1114 if (index == mLastVisiblePos) { 1115 updateScrollMax(); 1116 } 1117 mChildrenStates.loadView(v, index); 1118 } 1119 }; 1120 1121 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1122 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1123 : v.getMeasuredWidth(); 1124 if (mFixedRowSizeSecondary > 0) { 1125 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1126 } 1127 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1128 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1129 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1130 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1131 // do nothing 1132 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1133 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1134 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1135 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1136 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1137 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1138 } 1139 int left, top, right, bottom; 1140 if (mOrientation == HORIZONTAL) { 1141 left = start; 1142 top = startSecondary; 1143 right = end; 1144 bottom = startSecondary + sizeSecondary; 1145 } else { 1146 top = start; 1147 left = startSecondary; 1148 bottom = end; 1149 right = startSecondary + sizeSecondary; 1150 } 1151 v.layout(left, top, right, bottom); 1152 updateChildOpticalInsets(v, left, top, right, bottom); 1153 updateChildAlignments(v); 1154 } 1155 1156 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1157 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1158 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1159 v.getRight() - right, v.getBottom() - bottom); 1160 } 1161 1162 private void updateChildAlignments(View v) { 1163 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1164 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1165 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1166 } 1167 1168 private void updateChildAlignments() { 1169 for (int i = 0, c = getChildCount(); i < c; i++) { 1170 updateChildAlignments(getChildAt(i)); 1171 } 1172 } 1173 1174 private boolean needsAppendVisibleItem() { 1175 if (mLastVisiblePos < mFocusPosition) { 1176 return true; 1177 } 1178 int right = mScrollOffsetPrimary + mSizePrimary; 1179 for (int i = 0; i < mNumRows; i++) { 1180 if (mRows[i].low == mRows[i].high) { 1181 if (mRows[i].high < right) { 1182 return true; 1183 } 1184 } else if (mRows[i].high < right - mMarginPrimary) { 1185 return true; 1186 } 1187 } 1188 return false; 1189 } 1190 1191 private boolean needsPrependVisibleItem() { 1192 if (mFirstVisiblePos > mFocusPosition) { 1193 return true; 1194 } 1195 for (int i = 0; i < mNumRows; i++) { 1196 if (mRows[i].low == mRows[i].high) { 1197 if (mRows[i].low > mScrollOffsetPrimary) { 1198 return true; 1199 } 1200 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1201 return true; 1202 } 1203 } 1204 return false; 1205 } 1206 1207 // Append one column if possible and return true if reach end. 1208 private boolean appendOneVisibleItem() { 1209 while (true) { 1210 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1211 mLastVisiblePos < mGrid.getLastIndex()) { 1212 // append invisible view of saved location till last row 1213 final int index = mLastVisiblePos + 1; 1214 final int row = mGrid.getLocation(index).row; 1215 mGridProvider.createItem(index, row, true); 1216 if (row == mNumRows - 1) { 1217 return false; 1218 } 1219 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1220 (mLastVisiblePos != NO_POSITION && 1221 mLastVisiblePos < mState.getItemCount() - 1)) { 1222 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1223 return false; 1224 } else { 1225 return true; 1226 } 1227 } 1228 } 1229 1230 private void appendVisibleItems() { 1231 while (needsAppendVisibleItem()) { 1232 if (appendOneVisibleItem()) { 1233 break; 1234 } 1235 } 1236 } 1237 1238 // Prepend one column if possible and return true if reach end. 1239 private boolean prependOneVisibleItem() { 1240 while (true) { 1241 if (mFirstVisiblePos > 0) { 1242 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1243 // prepend invisible view of saved location till first row 1244 final int index = mFirstVisiblePos - 1; 1245 final int row = mGrid.getLocation(index).row; 1246 mGridProvider.createItem(index, row, false); 1247 if (row == 0) { 1248 return false; 1249 } 1250 } else { 1251 mGrid.prependItems(mScrollOffsetPrimary); 1252 return false; 1253 } 1254 } else { 1255 return true; 1256 } 1257 } 1258 } 1259 1260 private void prependVisibleItems() { 1261 while (needsPrependVisibleItem()) { 1262 if (prependOneVisibleItem()) { 1263 break; 1264 } 1265 } 1266 } 1267 1268 private void removeChildAt(int position) { 1269 View v = findViewByPosition(position); 1270 if (v != null) { 1271 if (DEBUG) { 1272 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1273 } 1274 mChildrenStates.saveOffscreenView(v, position); 1275 removeAndRecycleView(v, mRecycler); 1276 } 1277 } 1278 1279 private void removeInvisibleViewsAtEnd() { 1280 if (!mPruneChild) { 1281 return; 1282 } 1283 boolean update = false; 1284 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1285 View view = findViewByPosition(mLastVisiblePos); 1286 if (getViewMin(view) > mSizePrimary) { 1287 removeChildAt(mLastVisiblePos); 1288 mLastVisiblePos--; 1289 update = true; 1290 } else { 1291 break; 1292 } 1293 } 1294 if (update) { 1295 updateRowsMinMax(); 1296 } 1297 } 1298 1299 private void removeInvisibleViewsAtFront() { 1300 if (!mPruneChild) { 1301 return; 1302 } 1303 boolean update = false; 1304 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1305 View view = findViewByPosition(mFirstVisiblePos); 1306 if (getViewMax(view) < 0) { 1307 removeChildAt(mFirstVisiblePos); 1308 mFirstVisiblePos++; 1309 update = true; 1310 } else { 1311 break; 1312 } 1313 } 1314 if (update) { 1315 updateRowsMinMax(); 1316 } 1317 } 1318 1319 private void updateRowsMinMax() { 1320 if (mFirstVisiblePos < 0) { 1321 return; 1322 } 1323 for (int i = 0; i < mNumRows; i++) { 1324 mRows[i].low = Integer.MAX_VALUE; 1325 mRows[i].high = Integer.MIN_VALUE; 1326 } 1327 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1328 View view = findViewByPosition(i); 1329 int row = mGrid.getLocation(i).row; 1330 int low = getViewMin(view) + mScrollOffsetPrimary; 1331 if (low < mRows[row].low) { 1332 mRows[row].low = low; 1333 } 1334 int high = getViewMax(view) + mScrollOffsetPrimary; 1335 if (high > mRows[row].high) { 1336 mRows[row].high = high; 1337 } 1338 } 1339 } 1340 1341 // Fast layout when there is no structure change, adapter change, etc. 1342 protected void fastRelayout(boolean scrollToFocus) { 1343 initScrollController(); 1344 1345 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1346 1347 // relayout and repositioning views on each row 1348 for (int i = 0; i < mNumRows; i++) { 1349 List<Integer> row = rows[i]; 1350 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1351 for (int j = 0, size = row.size(); j < size; j++) { 1352 final int position = row.get(j); 1353 final View view = findViewByPosition(position); 1354 int primaryDelta, start, end; 1355 1356 if (mOrientation == HORIZONTAL) { 1357 final int primarySize = view.getMeasuredWidth(); 1358 if (view.isLayoutRequested()) { 1359 measureChild(view); 1360 } 1361 start = getViewMin(view); 1362 end = start + view.getMeasuredWidth(); 1363 primaryDelta = view.getMeasuredWidth() - primarySize; 1364 if (primaryDelta != 0) { 1365 for (int k = j + 1; k < size; k++) { 1366 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1367 } 1368 } 1369 } else { 1370 final int primarySize = view.getMeasuredHeight(); 1371 if (view.isLayoutRequested()) { 1372 measureChild(view); 1373 } 1374 start = getViewMin(view); 1375 end = start + view.getMeasuredHeight(); 1376 primaryDelta = view.getMeasuredHeight() - primarySize; 1377 if (primaryDelta != 0) { 1378 for (int k = j + 1; k < size; k++) { 1379 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1380 } 1381 } 1382 } 1383 layoutChild(i, view, start, end, startSecondary); 1384 } 1385 } 1386 1387 updateRowsMinMax(); 1388 appendVisibleItems(); 1389 prependVisibleItems(); 1390 1391 updateRowsMinMax(); 1392 updateScrollMin(); 1393 updateScrollMax(); 1394 updateScrollSecondAxis(); 1395 1396 if (scrollToFocus) { 1397 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1398 scrollToView(focusView, false); 1399 } 1400 } 1401 1402 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1403 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1404 for (int i = getChildCount() - 1; i >= 0; i--) { 1405 removeAndRecycleViewAt(i, recycler); 1406 } 1407 } 1408 1409 // Lays out items based on the current scroll position 1410 @Override 1411 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1412 if (DEBUG) { 1413 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1414 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1415 + " inPreLayout " + state.isPreLayout() 1416 + " didStructureChange " + state.didStructureChange() 1417 + " mForceFullLayout " + mForceFullLayout); 1418 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1419 } 1420 1421 if (mNumRows == 0) { 1422 // haven't done measure yet 1423 return; 1424 } 1425 final int itemCount = state.getItemCount(); 1426 if (itemCount < 0) { 1427 return; 1428 } 1429 1430 if (!mLayoutEnabled) { 1431 discardLayoutInfo(); 1432 removeAndRecycleAllViews(recycler); 1433 return; 1434 } 1435 mInLayout = true; 1436 1437 if (mLoadingState != null) { 1438 mFocusPosition = mLoadingState.index; 1439 mFocusPositionOffset = 0; 1440 mChildrenStates.getChildStates().putAll(mLoadingState.childStates); 1441 mLoadingState = null; 1442 } 1443 final boolean scrollToFocus = !isSmoothScrolling() 1444 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1445 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1446 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1447 mFocusPositionOffset = 0; 1448 } 1449 saveContext(recycler, state); 1450 // Track the old focus view so we can adjust our system scroll position 1451 // so that any scroll animations happening now will remain valid. 1452 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1453 // So we cache the deltas in PreLayout and use it in second layout. 1454 int delta = 0, deltaSecondary = 0; 1455 if (mFocusPosition != NO_POSITION && scrollToFocus) { 1456 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1457 View focusView = findViewByPosition(mFocusPosition); 1458 if (focusView != null) { 1459 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1460 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1461 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1462 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1463 false, false) - mScrollOffsetSecondary; 1464 } 1465 } 1466 1467 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1468 int savedFocusPos = mFocusPosition; 1469 boolean fastRelayout = false; 1470 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1471 fastRelayout = true; 1472 fastRelayout(scrollToFocus); 1473 } else { 1474 boolean hadFocus = mBaseGridView.hasFocus(); 1475 1476 int newFocusPosition = init(mFocusPosition); 1477 if (DEBUG) { 1478 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1479 + newFocusPosition); 1480 } 1481 1482 // depending on result of init(), either recreating everything 1483 // or try to reuse the row start positions near mFocusPosition 1484 if (mGrid.getSize() == 0) { 1485 // this is a fresh creating all items, starting from 1486 // mFocusPosition with a estimated row index. 1487 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1488 1489 // Can't track the old focus view 1490 delta = deltaSecondary = 0; 1491 1492 } else { 1493 // mGrid remembers Locations for the column that 1494 // contains mFocusePosition and also mRows remembers start 1495 // positions of each row. 1496 // Manually re-create child views for that column 1497 int firstIndex = mGrid.getFirstIndex(); 1498 int lastIndex = mGrid.getLastIndex(); 1499 for (int i = firstIndex; i <= lastIndex; i++) { 1500 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1501 } 1502 } 1503 // add visible views at end until reach the end of window 1504 appendVisibleItems(); 1505 // add visible views at front until reach the start of window 1506 prependVisibleItems(); 1507 // multiple rounds: scrollToView of first round may drag first/last child into 1508 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1509 int oldFirstVisible; 1510 int oldLastVisible; 1511 do { 1512 updateScrollMin(); 1513 updateScrollMax(); 1514 oldFirstVisible = mFirstVisiblePos; 1515 oldLastVisible = mLastVisiblePos; 1516 View focusView = findViewByPosition(newFocusPosition); 1517 // we need force to initialize the child view's position 1518 scrollToView(focusView, false); 1519 if (focusView != null && hadFocus) { 1520 focusView.requestFocus(); 1521 } 1522 appendVisibleItems(); 1523 prependVisibleItems(); 1524 removeInvisibleViewsAtFront(); 1525 removeInvisibleViewsAtEnd(); 1526 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1527 } 1528 mForceFullLayout = false; 1529 1530 if (scrollToFocus) { 1531 scrollDirectionPrimary(-delta); 1532 scrollDirectionSecondary(-deltaSecondary); 1533 } 1534 appendVisibleItems(); 1535 prependVisibleItems(); 1536 removeInvisibleViewsAtFront(); 1537 removeInvisibleViewsAtEnd(); 1538 1539 if (DEBUG) { 1540 StringWriter sw = new StringWriter(); 1541 PrintWriter pw = new PrintWriter(sw); 1542 mGrid.debugPrint(pw); 1543 Log.d(getTag(), sw.toString()); 1544 } 1545 1546 if (mRowSecondarySizeRefresh) { 1547 mRowSecondarySizeRefresh = false; 1548 } else { 1549 updateRowSecondarySizeRefresh(); 1550 } 1551 1552 if (!fastRelayout || mFocusPosition != savedFocusPos) { 1553 dispatchChildSelected(); 1554 } 1555 mInLayout = false; 1556 leaveContext(); 1557 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1558 } 1559 1560 private void offsetChildrenSecondary(int increment) { 1561 final int childCount = getChildCount(); 1562 if (mOrientation == HORIZONTAL) { 1563 for (int i = 0; i < childCount; i++) { 1564 getChildAt(i).offsetTopAndBottom(increment); 1565 } 1566 } else { 1567 for (int i = 0; i < childCount; i++) { 1568 getChildAt(i).offsetLeftAndRight(increment); 1569 } 1570 } 1571 } 1572 1573 private void offsetChildrenPrimary(int increment) { 1574 final int childCount = getChildCount(); 1575 if (mOrientation == VERTICAL) { 1576 for (int i = 0; i < childCount; i++) { 1577 getChildAt(i).offsetTopAndBottom(increment); 1578 } 1579 } else { 1580 for (int i = 0; i < childCount; i++) { 1581 getChildAt(i).offsetLeftAndRight(increment); 1582 } 1583 } 1584 } 1585 1586 @Override 1587 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1588 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1589 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1590 return 0; 1591 } 1592 saveContext(recycler, state); 1593 int result; 1594 if (mOrientation == HORIZONTAL) { 1595 result = scrollDirectionPrimary(dx); 1596 } else { 1597 result = scrollDirectionSecondary(dx); 1598 } 1599 leaveContext(); 1600 return result; 1601 } 1602 1603 @Override 1604 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1605 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1606 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1607 return 0; 1608 } 1609 saveContext(recycler, state); 1610 int result; 1611 if (mOrientation == VERTICAL) { 1612 result = scrollDirectionPrimary(dy); 1613 } else { 1614 result = scrollDirectionSecondary(dy); 1615 } 1616 leaveContext(); 1617 return result; 1618 } 1619 1620 // scroll in main direction may add/prune views 1621 private int scrollDirectionPrimary(int da) { 1622 if (da > 0) { 1623 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1624 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1625 if (mScrollOffsetPrimary + da > maxScroll) { 1626 da = maxScroll - mScrollOffsetPrimary; 1627 } 1628 } 1629 } else if (da < 0) { 1630 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1631 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1632 if (mScrollOffsetPrimary + da < minScroll) { 1633 da = minScroll - mScrollOffsetPrimary; 1634 } 1635 } 1636 } 1637 if (da == 0) { 1638 return 0; 1639 } 1640 offsetChildrenPrimary(-da); 1641 mScrollOffsetPrimary += da; 1642 if (mInLayout) { 1643 return da; 1644 } 1645 1646 int childCount = getChildCount(); 1647 boolean updated; 1648 1649 if (da > 0) { 1650 appendVisibleItems(); 1651 } else if (da < 0) { 1652 prependVisibleItems(); 1653 } 1654 updated = getChildCount() > childCount; 1655 childCount = getChildCount(); 1656 1657 if (da > 0) { 1658 removeInvisibleViewsAtFront(); 1659 } else if (da < 0) { 1660 removeInvisibleViewsAtEnd(); 1661 } 1662 updated |= getChildCount() < childCount; 1663 1664 if (updated) { 1665 updateRowSecondarySizeRefresh(); 1666 } 1667 1668 mBaseGridView.invalidate(); 1669 return da; 1670 } 1671 1672 // scroll in second direction will not add/prune views 1673 private int scrollDirectionSecondary(int dy) { 1674 if (dy == 0) { 1675 return 0; 1676 } 1677 offsetChildrenSecondary(-dy); 1678 mScrollOffsetSecondary += dy; 1679 mBaseGridView.invalidate(); 1680 return dy; 1681 } 1682 1683 private void updateScrollMax() { 1684 if (mLastVisiblePos < 0) { 1685 return; 1686 } 1687 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1688 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1689 if (!lastAvailable && maxUnknown) { 1690 return; 1691 } 1692 int maxEdge = Integer.MIN_VALUE; 1693 int rowIndex = -1; 1694 for (int i = 0; i < mRows.length; i++) { 1695 if (mRows[i].high > maxEdge) { 1696 maxEdge = mRows[i].high; 1697 rowIndex = i; 1698 } 1699 } 1700 int maxScroll = Integer.MAX_VALUE; 1701 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1702 StaggeredGrid.Location location = mGrid.getLocation(i); 1703 if (location != null && location.row == rowIndex) { 1704 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1705 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1706 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1707 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1708 break; 1709 } 1710 } 1711 if (lastAvailable) { 1712 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1713 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1714 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1715 " scrollMax to " + maxScroll); 1716 } else { 1717 // the maxScroll for currently last visible item is larger, 1718 // so we must invalidate the max scroll value. 1719 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1720 mWindowAlignment.mainAxis().invalidateScrollMax(); 1721 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1722 + "greater than " + maxScroll); 1723 } 1724 } 1725 } 1726 1727 private void updateScrollMin() { 1728 if (mFirstVisiblePos < 0) { 1729 return; 1730 } 1731 final boolean firstAvailable = mFirstVisiblePos == 0; 1732 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1733 if (!firstAvailable && minUnknown) { 1734 return; 1735 } 1736 int minEdge = Integer.MAX_VALUE; 1737 int rowIndex = -1; 1738 for (int i = 0; i < mRows.length; i++) { 1739 if (mRows[i].low < minEdge) { 1740 minEdge = mRows[i].low; 1741 rowIndex = i; 1742 } 1743 } 1744 int minScroll = Integer.MIN_VALUE; 1745 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1746 StaggeredGrid.Location location = mGrid.getLocation(i); 1747 if (location != null && location.row == rowIndex) { 1748 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1749 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1750 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1751 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1752 break; 1753 } 1754 } 1755 if (firstAvailable) { 1756 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1757 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1758 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1759 " scrollMin to " + minScroll); 1760 } else { 1761 // the minScroll for currently first visible item is smaller, 1762 // so we must invalidate the min scroll value. 1763 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1764 mWindowAlignment.mainAxis().invalidateScrollMin(); 1765 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1766 + "less than " + minScroll); 1767 } 1768 } 1769 } 1770 1771 private void updateScrollSecondAxis() { 1772 mWindowAlignment.secondAxis().setMinEdge(0); 1773 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1774 } 1775 1776 private void initScrollController() { 1777 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1778 // e.g. when topPadding is 16 for horizontal grid view, the initial 1779 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1780 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1781 // fastLayout() is performed 1782 int paddingPrimaryDiff, paddingSecondaryDiff; 1783 if (mOrientation == HORIZONTAL) { 1784 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1785 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1786 } else { 1787 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1788 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1789 } 1790 mScrollOffsetPrimary -= paddingPrimaryDiff; 1791 mScrollOffsetSecondary -= paddingSecondaryDiff; 1792 1793 mWindowAlignment.horizontal.setSize(getWidth()); 1794 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1795 mWindowAlignment.vertical.setSize(getHeight()); 1796 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1797 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1798 1799 if (DEBUG) { 1800 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1801 + " mWindowAlignment " + mWindowAlignment); 1802 } 1803 } 1804 1805 public void setSelection(RecyclerView parent, int position) { 1806 setSelection(parent, position, false); 1807 } 1808 1809 public void setSelectionSmooth(RecyclerView parent, int position) { 1810 setSelection(parent, position, true); 1811 } 1812 1813 public int getSelection() { 1814 return mFocusPosition; 1815 } 1816 1817 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1818 if (mFocusPosition == position) { 1819 return; 1820 } 1821 View view = findViewByPosition(position); 1822 if (view != null) { 1823 mInSelection = true; 1824 scrollToView(view, smooth); 1825 mInSelection = false; 1826 } else { 1827 mFocusPosition = position; 1828 mFocusPositionOffset = 0; 1829 if (!mLayoutEnabled) { 1830 return; 1831 } 1832 if (smooth) { 1833 if (!hasDoneFirstLayout()) { 1834 Log.w(getTag(), "setSelectionSmooth should " + 1835 "not be called before first layout pass"); 1836 return; 1837 } 1838 LinearSmoothScroller linearSmoothScroller = 1839 new LinearSmoothScroller(parent.getContext()) { 1840 @Override 1841 public PointF computeScrollVectorForPosition(int targetPosition) { 1842 if (getChildCount() == 0) { 1843 return null; 1844 } 1845 final int firstChildPos = getPosition(getChildAt(0)); 1846 final int direction = targetPosition < firstChildPos ? -1 : 1; 1847 if (mOrientation == HORIZONTAL) { 1848 return new PointF(direction, 0); 1849 } else { 1850 return new PointF(0, direction); 1851 } 1852 } 1853 @Override 1854 protected void onTargetFound(View targetView, 1855 RecyclerView.State state, Action action) { 1856 if (hasFocus()) { 1857 targetView.requestFocus(); 1858 } 1859 dispatchChildSelected(); 1860 if (getScrollPosition(targetView, mTempDeltas)) { 1861 int dx, dy; 1862 if (mOrientation == HORIZONTAL) { 1863 dx = mTempDeltas[0]; 1864 dy = mTempDeltas[1]; 1865 } else { 1866 dx = mTempDeltas[1]; 1867 dy = mTempDeltas[0]; 1868 } 1869 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1870 final int time = calculateTimeForDeceleration(distance); 1871 action.update(dx, dy, time, mDecelerateInterpolator); 1872 } 1873 } 1874 }; 1875 linearSmoothScroller.setTargetPosition(position); 1876 startSmoothScroll(linearSmoothScroller); 1877 } else { 1878 mForceFullLayout = true; 1879 parent.requestLayout(); 1880 } 1881 } 1882 } 1883 1884 @Override 1885 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1886 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1887 int pos = mFocusPosition + mFocusPositionOffset; 1888 if (positionStart <= pos) { 1889 mFocusPositionOffset += itemCount; 1890 } 1891 } 1892 } 1893 1894 @Override 1895 public void onItemsChanged(RecyclerView recyclerView) { 1896 mFocusPositionOffset = 0; 1897 } 1898 1899 @Override 1900 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1901 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1902 int pos = mFocusPosition + mFocusPositionOffset; 1903 if (positionStart <= pos) { 1904 if (positionStart + itemCount > pos) { 1905 // stop updating offset after the focus item was removed 1906 mFocusPositionOffset = Integer.MIN_VALUE; 1907 } else { 1908 mFocusPositionOffset -= itemCount; 1909 } 1910 } 1911 } 1912 } 1913 1914 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1915 int itemCount) { 1916 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1917 int pos = mFocusPosition + mFocusPositionOffset; 1918 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1919 // moved items include focused position 1920 mFocusPositionOffset += toPosition - fromPosition; 1921 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1922 // move items before focus position to after focused position 1923 mFocusPositionOffset -= itemCount; 1924 } else if (fromPosition > pos && toPosition < pos) { 1925 // move items after focus position to before focused position 1926 mFocusPositionOffset += itemCount; 1927 } 1928 } 1929 } 1930 1931 @Override 1932 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1933 if (mFocusSearchDisabled) { 1934 return true; 1935 } 1936 if (!mInLayout && !mInSelection) { 1937 scrollToView(child, true); 1938 } 1939 return true; 1940 } 1941 1942 @Override 1943 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1944 boolean immediate) { 1945 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1946 return false; 1947 } 1948 1949 int getScrollOffsetX() { 1950 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1951 } 1952 1953 int getScrollOffsetY() { 1954 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1955 } 1956 1957 public void getViewSelectedOffsets(View view, int[] offsets) { 1958 if (mOrientation == HORIZONTAL) { 1959 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1960 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1961 } else { 1962 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1963 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1964 } 1965 } 1966 1967 private int getPrimarySystemScrollPosition(View view) { 1968 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1969 int pos = getPositionByView(view); 1970 StaggeredGrid.Location location = mGrid.getLocation(pos); 1971 final int row = location.row; 1972 boolean isFirst = mFirstVisiblePos == 0; 1973 // TODO: change to use State object in onRequestChildFocus() 1974 boolean isLast = mLastVisiblePos == (mState == null ? 1975 getItemCount() : mState.getItemCount()) - 1; 1976 if (isFirst || isLast) { 1977 for (int i = getChildCount() - 1; i >= 0; i--) { 1978 int position = getPositionByIndex(i); 1979 StaggeredGrid.Location loc = mGrid.getLocation(position); 1980 if (loc != null && loc.row == row) { 1981 if (position < pos) { 1982 isFirst = false; 1983 } else if (position > pos) { 1984 isLast = false; 1985 } 1986 } 1987 } 1988 } 1989 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 1990 } 1991 1992 private int getSecondarySystemScrollPosition(View view) { 1993 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1994 int pos = getPositionByView(view); 1995 StaggeredGrid.Location location = mGrid.getLocation(pos); 1996 final int row = location.row; 1997 boolean isFirst = row == 0; 1998 boolean isLast = row == mGrid.getNumRows() - 1; 1999 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2000 isFirst, isLast); 2001 } 2002 2003 /** 2004 * Scroll to a given child view and change mFocusPosition. 2005 */ 2006 private void scrollToView(View view, boolean smooth) { 2007 int newFocusPosition = getPositionByView(view); 2008 if (newFocusPosition != mFocusPosition) { 2009 mFocusPosition = newFocusPosition; 2010 mFocusPositionOffset = 0; 2011 if (!mInLayout) { 2012 dispatchChildSelected(); 2013 } 2014 } 2015 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2016 mBaseGridView.invalidate(); 2017 } 2018 if (view == null) { 2019 return; 2020 } 2021 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2022 // transfer focus to the child if it does not have focus yet (e.g. triggered 2023 // by setSelection()) 2024 view.requestFocus(); 2025 } 2026 if (!mScrollEnabled) { 2027 return; 2028 } 2029 if (getScrollPosition(view, mTempDeltas)) { 2030 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2031 } 2032 } 2033 2034 private boolean getScrollPosition(View view, int[] deltas) { 2035 switch (mFocusScrollStrategy) { 2036 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2037 default: 2038 return getAlignedPosition(view, deltas); 2039 case BaseGridView.FOCUS_SCROLL_ITEM: 2040 case BaseGridView.FOCUS_SCROLL_PAGE: 2041 return getNoneAlignedPosition(view, deltas); 2042 } 2043 } 2044 2045 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2046 int pos = getPositionByView(view); 2047 int viewMin = getViewMin(view); 2048 int viewMax = getViewMax(view); 2049 // we either align "firstView" to left/top padding edge 2050 // or align "lastView" to right/bottom padding edge 2051 View firstView = null; 2052 View lastView = null; 2053 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2054 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2055 final int row = mGrid.getLocation(pos).row; 2056 if (viewMin < paddingLow) { 2057 // view enters low padding area: 2058 firstView = view; 2059 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2060 // scroll one "page" left/top, 2061 // align first visible item of the "page" at the low padding edge. 2062 while (!prependOneVisibleItem()) { 2063 List<Integer> positions = 2064 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2065 firstView = findViewByPosition(positions.get(0)); 2066 if (viewMax - getViewMin(firstView) > clientSize) { 2067 if (positions.size() > 1) { 2068 firstView = findViewByPosition(positions.get(1)); 2069 } 2070 break; 2071 } 2072 } 2073 } 2074 } else if (viewMax > clientSize + paddingLow) { 2075 // view enters high padding area: 2076 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2077 // scroll whole one page right/bottom, align view at the low padding edge. 2078 firstView = view; 2079 do { 2080 List<Integer> positions = 2081 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2082 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2083 if (getViewMax(lastView) - viewMin > clientSize) { 2084 lastView = null; 2085 break; 2086 } 2087 } while (!appendOneVisibleItem()); 2088 if (lastView != null) { 2089 // however if we reached end, we should align last view. 2090 firstView = null; 2091 } 2092 } else { 2093 lastView = view; 2094 } 2095 } 2096 int scrollPrimary = 0; 2097 int scrollSecondary = 0; 2098 if (firstView != null) { 2099 scrollPrimary = getViewMin(firstView) - paddingLow; 2100 } else if (lastView != null) { 2101 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2102 } 2103 View secondaryAlignedView; 2104 if (firstView != null) { 2105 secondaryAlignedView = firstView; 2106 } else if (lastView != null) { 2107 secondaryAlignedView = lastView; 2108 } else { 2109 secondaryAlignedView = view; 2110 } 2111 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2112 scrollSecondary -= mScrollOffsetSecondary; 2113 if (scrollPrimary != 0 || scrollSecondary != 0) { 2114 deltas[0] = scrollPrimary; 2115 deltas[1] = scrollSecondary; 2116 return true; 2117 } 2118 return false; 2119 } 2120 2121 private boolean getAlignedPosition(View view, int[] deltas) { 2122 int scrollPrimary = getPrimarySystemScrollPosition(view); 2123 int scrollSecondary = getSecondarySystemScrollPosition(view); 2124 if (DEBUG) { 2125 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2126 +" " + mWindowAlignment); 2127 } 2128 scrollPrimary -= mScrollOffsetPrimary; 2129 scrollSecondary -= mScrollOffsetSecondary; 2130 if (scrollPrimary != 0 || scrollSecondary != 0) { 2131 deltas[0] = scrollPrimary; 2132 deltas[1] = scrollSecondary; 2133 return true; 2134 } 2135 return false; 2136 } 2137 2138 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2139 if (mInLayout) { 2140 scrollDirectionPrimary(scrollPrimary); 2141 scrollDirectionSecondary(scrollSecondary); 2142 } else { 2143 int scrollX; 2144 int scrollY; 2145 if (mOrientation == HORIZONTAL) { 2146 scrollX = scrollPrimary; 2147 scrollY = scrollSecondary; 2148 } else { 2149 scrollX = scrollSecondary; 2150 scrollY = scrollPrimary; 2151 } 2152 if (smooth) { 2153 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2154 } else { 2155 mBaseGridView.scrollBy(scrollX, scrollY); 2156 } 2157 } 2158 } 2159 2160 public void setPruneChild(boolean pruneChild) { 2161 if (mPruneChild != pruneChild) { 2162 mPruneChild = pruneChild; 2163 if (mPruneChild) { 2164 requestLayout(); 2165 } 2166 } 2167 } 2168 2169 public boolean getPruneChild() { 2170 return mPruneChild; 2171 } 2172 2173 public void setScrollEnabled(boolean scrollEnabled) { 2174 if (mScrollEnabled != scrollEnabled) { 2175 mScrollEnabled = scrollEnabled; 2176 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2177 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : 2178 mFocusPosition); 2179 if (focusView != null) { 2180 scrollToView(focusView, true); 2181 } 2182 } 2183 } 2184 } 2185 2186 public boolean isScrollEnabled() { 2187 return mScrollEnabled; 2188 } 2189 2190 private int findImmediateChildIndex(View view) { 2191 while (view != null && view != mBaseGridView) { 2192 int index = mBaseGridView.indexOfChild(view); 2193 if (index >= 0) { 2194 return index; 2195 } 2196 view = (View) view.getParent(); 2197 } 2198 return NO_POSITION; 2199 } 2200 2201 void setFocusSearchDisabled(boolean disabled) { 2202 mFocusSearchDisabled = disabled; 2203 } 2204 2205 boolean isFocusSearchDisabled() { 2206 return mFocusSearchDisabled; 2207 } 2208 2209 @Override 2210 public View onInterceptFocusSearch(View focused, int direction) { 2211 if (mFocusSearchDisabled) { 2212 return focused; 2213 } 2214 return null; 2215 } 2216 2217 boolean hasPreviousViewInSameRow(int pos) { 2218 if (mGrid == null || pos == NO_POSITION) { 2219 return false; 2220 } 2221 if (mFirstVisiblePos > 0) { 2222 return true; 2223 } 2224 final int focusedRow = mGrid.getLocation(pos).row; 2225 for (int i = getChildCount() - 1; i >= 0; i--) { 2226 int position = getPositionByIndex(i); 2227 StaggeredGrid.Location loc = mGrid.getLocation(position); 2228 if (loc != null && loc.row == focusedRow) { 2229 if (position < pos) { 2230 return true; 2231 } 2232 } 2233 } 2234 return false; 2235 } 2236 2237 @Override 2238 public boolean onAddFocusables(RecyclerView recyclerView, 2239 ArrayList<View> views, int direction, int focusableMode) { 2240 if (mFocusSearchDisabled) { 2241 return true; 2242 } 2243 // If this viewgroup or one of its children currently has focus then we 2244 // consider our children for focus searching in main direction on the same row. 2245 // If this viewgroup has no focus and using focus align, we want the system 2246 // to ignore our children and pass focus to the viewgroup, which will pass 2247 // focus on to its children appropriately. 2248 // If this viewgroup has no focus and not using focus align, we want to 2249 // consider the child that does not overlap with padding area. 2250 if (recyclerView.hasFocus()) { 2251 final int movement = getMovement(direction); 2252 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2253 // Move on secondary direction uses default addFocusables(). 2254 return false; 2255 } 2256 final View focused = recyclerView.findFocus(); 2257 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2258 // Add focusables of focused item. 2259 if (focusedPos != NO_POSITION) { 2260 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2261 } 2262 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2263 mGrid.getLocation(focusedPos).row : NO_POSITION; 2264 // Add focusables of next neighbor of same row on the focus search direction. 2265 if (mGrid != null) { 2266 final int focusableCount = views.size(); 2267 for (int i = 0, count = getChildCount(); i < count; i++) { 2268 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2269 final View child = getChildAt(index); 2270 if (child.getVisibility() != View.VISIBLE) { 2271 continue; 2272 } 2273 int position = getPositionByIndex(index); 2274 StaggeredGrid.Location loc = mGrid.getLocation(position); 2275 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2276 if (focusedPos == NO_POSITION || 2277 (movement == NEXT_ITEM && position > focusedPos) 2278 || (movement == PREV_ITEM && position < focusedPos)) { 2279 child.addFocusables(views, direction, focusableMode); 2280 if (views.size() > focusableCount) { 2281 break; 2282 } 2283 } 2284 } 2285 } 2286 } 2287 } else { 2288 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2289 // adding views not overlapping padding area to avoid scrolling in gaining focus 2290 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2291 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2292 int focusableCount = views.size(); 2293 for (int i = 0, count = getChildCount(); i < count; i++) { 2294 View child = getChildAt(i); 2295 if (child.getVisibility() == View.VISIBLE) { 2296 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2297 child.addFocusables(views, direction, focusableMode); 2298 } 2299 } 2300 } 2301 // if we cannot find any, then just add all children. 2302 if (views.size() == focusableCount) { 2303 for (int i = 0, count = getChildCount(); i < count; i++) { 2304 View child = getChildAt(i); 2305 if (child.getVisibility() == View.VISIBLE) { 2306 child.addFocusables(views, direction, focusableMode); 2307 } 2308 } 2309 if (views.size() != focusableCount) { 2310 return true; 2311 } 2312 } else { 2313 return true; 2314 } 2315 // if still cannot find any, fall through and add itself 2316 } 2317 if (recyclerView.isFocusable()) { 2318 views.add(recyclerView); 2319 } 2320 } 2321 return true; 2322 } 2323 2324 @Override 2325 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2326 RecyclerView.State state) { 2327 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2328 2329 View view = null; 2330 int movement = getMovement(direction); 2331 if (mNumRows == 1) { 2332 // for simple row, use LinearSmoothScroller to smooth animation. 2333 // It will stay at a fixed cap speed in continuous scroll. 2334 if (movement == NEXT_ITEM) { 2335 int newPos = mFocusPosition + mNumRows; 2336 if (newPos < getItemCount()) { 2337 setSelectionSmooth(mBaseGridView, newPos); 2338 view = focused; 2339 } else { 2340 if (!mFocusOutEnd) { 2341 view = focused; 2342 } 2343 } 2344 } else if (movement == PREV_ITEM){ 2345 int newPos = mFocusPosition - mNumRows; 2346 if (newPos >= 0) { 2347 setSelectionSmooth(mBaseGridView, newPos); 2348 view = focused; 2349 } else { 2350 if (!mFocusOutFront) { 2351 view = focused; 2352 } 2353 } 2354 } 2355 } else if (mNumRows > 1) { 2356 // for possible staggered grid, we need guarantee focus to same row/column. 2357 // TODO: we may also use LinearSmoothScroller. 2358 saveContext(recycler, state); 2359 final FocusFinder ff = FocusFinder.getInstance(); 2360 if (movement == NEXT_ITEM) { 2361 while (view == null && !appendOneVisibleItem()) { 2362 view = ff.findNextFocus(mBaseGridView, focused, direction); 2363 } 2364 } else if (movement == PREV_ITEM){ 2365 while (view == null && !prependOneVisibleItem()) { 2366 view = ff.findNextFocus(mBaseGridView, focused, direction); 2367 } 2368 } 2369 if (view == null) { 2370 // returning the same view to prevent focus lost when scrolling past the end of the list 2371 if (movement == PREV_ITEM) { 2372 view = mFocusOutFront ? null : focused; 2373 } else if (movement == NEXT_ITEM){ 2374 view = mFocusOutEnd ? null : focused; 2375 } 2376 } 2377 leaveContext(); 2378 } 2379 if (DEBUG) Log.v(getTag(), "returning view " + view); 2380 return view; 2381 } 2382 2383 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2384 Rect previouslyFocusedRect) { 2385 switch (mFocusScrollStrategy) { 2386 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2387 default: 2388 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2389 direction, previouslyFocusedRect); 2390 case BaseGridView.FOCUS_SCROLL_PAGE: 2391 case BaseGridView.FOCUS_SCROLL_ITEM: 2392 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2393 direction, previouslyFocusedRect); 2394 } 2395 } 2396 2397 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2398 int direction, Rect previouslyFocusedRect) { 2399 View view = findViewByPosition(mFocusPosition); 2400 if (view != null) { 2401 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2402 if (!result && DEBUG) { 2403 Log.w(getTag(), "failed to request focus on " + view); 2404 } 2405 return result; 2406 } 2407 return false; 2408 } 2409 2410 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2411 int direction, Rect previouslyFocusedRect) { 2412 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2413 int index; 2414 int increment; 2415 int end; 2416 int count = getChildCount(); 2417 if ((direction & View.FOCUS_FORWARD) != 0) { 2418 index = 0; 2419 increment = 1; 2420 end = count; 2421 } else { 2422 index = count - 1; 2423 increment = -1; 2424 end = -1; 2425 } 2426 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2427 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2428 for (int i = index; i != end; i += increment) { 2429 View child = getChildAt(i); 2430 if (child.getVisibility() == View.VISIBLE) { 2431 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2432 if (child.requestFocus(direction, previouslyFocusedRect)) { 2433 return true; 2434 } 2435 } 2436 } 2437 } 2438 return false; 2439 } 2440 2441 private final static int PREV_ITEM = 0; 2442 private final static int NEXT_ITEM = 1; 2443 private final static int PREV_ROW = 2; 2444 private final static int NEXT_ROW = 3; 2445 2446 private int getMovement(int direction) { 2447 int movement = View.FOCUS_LEFT; 2448 2449 if (mOrientation == HORIZONTAL) { 2450 switch(direction) { 2451 case View.FOCUS_LEFT: 2452 movement = PREV_ITEM; 2453 break; 2454 case View.FOCUS_RIGHT: 2455 movement = NEXT_ITEM; 2456 break; 2457 case View.FOCUS_UP: 2458 movement = PREV_ROW; 2459 break; 2460 case View.FOCUS_DOWN: 2461 movement = NEXT_ROW; 2462 break; 2463 } 2464 } else if (mOrientation == VERTICAL) { 2465 switch(direction) { 2466 case View.FOCUS_LEFT: 2467 movement = PREV_ROW; 2468 break; 2469 case View.FOCUS_RIGHT: 2470 movement = NEXT_ROW; 2471 break; 2472 case View.FOCUS_UP: 2473 movement = PREV_ITEM; 2474 break; 2475 case View.FOCUS_DOWN: 2476 movement = NEXT_ITEM; 2477 break; 2478 } 2479 } 2480 2481 return movement; 2482 } 2483 2484 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2485 View view = findViewByPosition(mFocusPosition); 2486 if (view == null) { 2487 return i; 2488 } 2489 int focusIndex = recyclerView.indexOfChild(view); 2490 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2491 // drawing order is 0 1 2 3 9 8 7 6 5 4 2492 if (i < focusIndex) { 2493 return i; 2494 } else if (i < childCount - 1) { 2495 return focusIndex + childCount - 1 - i; 2496 } else { 2497 return focusIndex; 2498 } 2499 } 2500 2501 @Override 2502 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2503 RecyclerView.Adapter newAdapter) { 2504 discardLayoutInfo(); 2505 mFocusPosition = NO_POSITION; 2506 mFocusPositionOffset = 0; 2507 mLoadingState = null; 2508 mChildrenStates.clear(); 2509 super.onAdapterChanged(oldAdapter, newAdapter); 2510 } 2511 2512 private void discardLayoutInfo() { 2513 mGrid = null; 2514 mRows = null; 2515 mRowSizeSecondary = null; 2516 mFirstVisiblePos = -1; 2517 mLastVisiblePos = -1; 2518 mRowSecondarySizeRefresh = false; 2519 } 2520 2521 public void setLayoutEnabled(boolean layoutEnabled) { 2522 if (mLayoutEnabled != layoutEnabled) { 2523 mLayoutEnabled = layoutEnabled; 2524 requestLayout(); 2525 } 2526 } 2527 2528 final static class SavedState implements Parcelable { 2529 2530 int index; // index inside adapter of the current view 2531 Bundle childStates = Bundle.EMPTY; 2532 2533 @Override 2534 public void writeToParcel(Parcel out, int flags) { 2535 out.writeInt(index); 2536 out.writeBundle(childStates); 2537 } 2538 2539 @SuppressWarnings("hiding") 2540 public static final Parcelable.Creator<SavedState> CREATOR = 2541 new Parcelable.Creator<SavedState>() { 2542 @Override 2543 public SavedState createFromParcel(Parcel in) { 2544 return new SavedState(in); 2545 } 2546 2547 @Override 2548 public SavedState[] newArray(int size) { 2549 return new SavedState[size]; 2550 } 2551 }; 2552 2553 @Override 2554 public int describeContents() { 2555 return 0; 2556 } 2557 2558 SavedState(Parcel in) { 2559 index = in.readInt(); 2560 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2561 } 2562 2563 SavedState() { 2564 } 2565 } 2566 2567 @Override 2568 public Parcelable onSaveInstanceState() { 2569 SavedState ss = new SavedState(); 2570 for (int i = 0, count = getChildCount(); i < count; i++) { 2571 View view = getChildAt(i); 2572 int position = getPositionByView(view); 2573 if (position != NO_POSITION) { 2574 mChildrenStates.saveOnScreenView(view, position); 2575 } 2576 } 2577 ss.index = getSelection(); 2578 ss.childStates = mChildrenStates.getChildStates(); 2579 return ss; 2580 } 2581 2582 @Override 2583 public void onRestoreInstanceState(Parcelable state) { 2584 if (!(state instanceof SavedState)) { 2585 return; 2586 } 2587 SavedState ss = (SavedState)state; 2588 mLoadingState = ss; 2589 mForceFullLayout = true; 2590 requestLayout(); 2591 } 2592} 2593